| Title |
Donnan dialysis for phosphate recovery from diverted urine |
| ID_Doc |
24085 |
| Authors |
McCartney, SN; Fan, HQ; Watanabe, NS; Huang, YX; Yip, NY |
| Title |
Donnan dialysis for phosphate recovery from diverted urine |
| Year |
2022 |
| Published |
|
| DOI |
10.1016/j.watres.2022.119302 |
| Abstract |
There is a critical need to shift from existing linear phosphorous management practices to a more sustainable circular P economy. Closing the nutrient loop can reduce our reliance on phosphate mining, which has well-documented environmental impacts, while simultaneously alleviating P pollution of aquatic environments from wastewater discharges that are not completely treated. The high orthophosphate, HxPO4(3-x)-, content in source-separated urine offers propitious opportunities for P recovery. This study examines the use of Donnan dialysis (DD), an ion-exchange membrane-based process, for the recovery of orthophosphates from fresh and hydrolyzed urine matrixes. H2PO4- transport against an orthophosphate concentration gradient was demonstrated and orthophosphate recovery yields up to 93% were achieved. By adopting higher feed to receiver volume ratios, DD enriched orthophosphate in the product stream as high as approximate to 2.5 x the initial urine feed concentration. However, flux, selectivity, and yield of orthophosphate recovery were detrimentally impacted by the presence of SO42- and Cl- in fresh urine, and the large amount of HCO3- rendered hydrolyzed urine practically unsuitable for P recovery using DD. The detrimental effects of sulfate ions can be mitigated by utilizing a monovalent ion permselective membrane, improving selectivity for H2PO4- transport over SO42- by 3.1 x relative to DD with a conventional membrane; but the enhancement was at the expense of reduced orthophosphate flux. Critically, widely available and low-cost/waste resources with sufficiently high Cl- content, such as seawater and waste water softening regenerant rinse, can be employed to improve the economic viability of orthophosphate recovery. This study shows the promising potential of DD for P recovery and enrichment from source-separated urine. |
| Author Keywords |
Phosphorous; Nutrient recovery; Donnan dialysis; Urine; Circular economy |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:000884461000002 |
| WoS Category |
Engineering, Environmental; Environmental Sciences; Water Resources |
| Research Area |
Engineering; Environmental Sciences & Ecology; Water Resources |
| PDF |
http://manuscript.elsevier.com/S0043135422012477/pdf/S0043135422012477.pdf
|